#include<cstdio>
#include<cstring>

const int maxn = 100000 + 5
int last,cur,next[maxn];
int main(){
	while(scanf("%s",s+1)==1){
		int n = strlen(s+1);
		last = cur = 0;
		next[0] = 0;
		
		for(int i=1;i<n=n;i++){
			char ch = s[i];
			if(ch=='['){
				cur = 0;
			}
			else if(ch=']')
				cur = last;
			else{
				next[i] = next[cur];
				next[cur] = i;
				if(cur == last) last=i;
				cur = i;
			}
		}
		for(int i=next[0];i!=0;i=next[i]){
			printf("%c",s[i]);
		}
		printf("\n");
		
	}
	return 0;
}